Interleukin-1 (hereinafter referred to as IL-1) is a protein having a molecular weight of 17.5 kDa which is produced by a variety of cells in the body such as macrophage, monocyte, neutrophil, fibroblast, skin keratinocyte, hepatic Kupffer cell, renal glomerular mesangial cell, brain astroglia, and angioendothelial cell. IL-1 includes .alpha.-form having an isoelectric point (pI) of 5 and .beta.-form having pI of 7. At present, it is known that the .alpha.-form and the .beta.-form exhibit the same activity.
IL-1 is known to have various biological activities. That is, IL-1 is deemed to act as a factor that enhances multiplicative division of lymphocytes and as a cofactor that enhances multiplication of B cells and production of antibodies. Further, it is considered that IL-1 acts on arachidonic acid cascade in the temperature center of the hypothalamus to increase the synthesis of prostaglandin E.sub.2, thereby causing pyrexia. Furthermore, it is shown that the activity of IL-1 is significantly increased in the serum of patients suffering from septicemia or Crohn's disease and in the cavum articulare of patients who suffer from articular rheumatism. This suggests the participation of IL-1 in the attack and progress of these diseases. Suppression of the production of IL-1 is considered to be effective for alleviating the symptoms that occur through IL-1.
Examples of known compounds having IL-1 production inhibitory activity are synthetic compounds such as naphthalene derivatives (Japanese Published Unexamined Patent Application No. 59743/92), 3-arylisothiazole derivatives (Japanese Published Unexamined Patent Application No. 74121/92), and zingerol derivatives (Japanese Published Unexamined Patent Application No. 202127/92).
There have been reports on aranorosin J. Antibiot., 41, 1780-1784 (1988), Japanese Published Unexamined Patent Application No. 157386/91!, and aranorosinol A and aranorosinol B J. Antibiot., 45, 1592-1598 (1992)!. However, the structures of these compounds are different from the structure of the compound represented by formula (I), and there has been no report on IL-1 production inhibition by any of these compounds.